To service users who get on a mobile vehicle such as a bus, a train, and a cruise ship, standards are recently considering a scenario that installs a Mobile Relay Station (MRS) in the vehicle to enable a Base Station (BS) or a fixed relay station to communicate with a terminal of the user via the MRS.
A first feature of the MRS based system is mobility. In this respect, techniques relating to the mobility management such as handover have been suggested, and researches are mostly conducted on a resource allocation based on the MRS mobility as the number of the MRSs within a cell increases. When a cellular system of the direct communication without the RS and the MRS based system coexist within a large cell, a conventional method proposes that the two systems divide and use resources in the same frequency band. In so doing, fundamentally, the resources are divided to be orthogonal to each other in time or in frequency.
Another feature of the MRS based system is economy of the power. A distance between the MRS installed in the mobile vehicle and the internal terminals is much shorter than a distance between the BS or the fixed RS and the terminals in the mobile vehicle. Accordingly, when an antenna for the MRS is installed in the mobile vehicle and the seamless communication between the BS and the MRS is feasible, the MRS can service the internal terminals with the little transmit power and with little interference to outside.
Up to the present, researches are primarily applied to the resource allocation method based on the mobility of the MRS and particular consideration is not given to the channel characteristic between the MRS and the internal terminal. Further, in the large cell including both of the cellular system and the MRS based system, when the number of the MRSs increases, what is needed is a method other than a method for allowing the two systems to divide and use the resources in the same frequency band.